提高 Pt-Bi 双金属催化剂氧还原反应活性的策略：密度泛函理论研究。

Strategies to Improve the Oxygen Reduction Reaction Activity on Pt-Bi Bimetallic Catalysts: A Density Functional Theory Study.

机构信息

Key Laboratory for Advanced Materials and Joint International Research Laboratory for Precision Chemistry and Molecular Engineering, Feringa Nobel Prize Scientist Joint Research Center, Centre for Computational Chemistry and Research Institute of Industrial Catalysis, School of Chemistry and Molecular Engineering, East China University of Science and Technology, 130 Meilong Road, Shanghai200237, China.

出版信息

J Phys Chem Lett. 2023 Feb 23;14(7):1990-1998. doi: 10.1021/acs.jpclett.2c03465. Epub 2023 Feb 16.

DOI:10.1021/acs.jpclett.2c03465

PMID:36815311

Abstract

Decreasing the level of use of Pt in proton exchange membrane fuel cells is of great research interest both academically and industrially. In this work, we systematically studied the oxygen reduction reaction (ORR) following the four-electron association mechanism at various Pt-Bi surfaces with density functional theory calculations. The results showed that the introduction of Bi changes the potential-determining step of ORR. Moreover, the hydroxy adsorption free energy () can be used as a descriptor of ORR activity, and 0.74 eV is the ideal for it to reach its maximum. Notably, we also found that the tensile strain introduced by Bi and electron transfer between Pt and Bi synergize to modulate the d-band of Pt to contract, shift downward, and break the 5d6s valence electron configuration of Pt, and accordingly, PtBi(100), with the lowest d-band center, gives the best ORR activity, which is even slightly higher than that of Pt(111).

摘要

降低质子交换膜燃料电池中铂的使用水平在学术和工业上都具有重要的研究意义。在这项工作中，我们使用密度泛函理论计算，系统地研究了各种 Pt-Bi 表面遵循四电子偶联机制的氧还原反应（ORR）。结果表明，Bi 的引入改变了 ORR 的速控步骤。此外，羟基吸附自由能（）可用作 ORR 活性的描述符，而 0.74 eV 是达到最大活性的理想值。值得注意的是，我们还发现 Bi 引入的拉伸应变和 Pt 与 Bi 之间的电子转移协同作用，调节 Pt 的 d 带收缩、下移并打破 Pt 的 5d6s 价电子构型，因此，具有最低 d 带中心的 PtBi(100) 具有最佳的 ORR 活性，甚至略高于 Pt(111)。